Ethanol production from corn has increased in recent years. The corn is typically ground to a course powder that is then mixed with water and yeast and fermented to produce a fermented mixture (sometimes referred to as “mash”) that contains residual solids, ethanol and other liquids. The other liquids include water, monoglycerides, diglycerides, triglycerides, glycerin, and free fatty acids. Typically, the liquid portion of the mash is heated to distill off the ethanol, which is captured and sold as an additive for automotive fuels.
The residual liquid remaining after the ethanol is removed contains free fatty acids and glycerol and from 1% to 3% by weight monoglycerides, diglycerids, triglycerides. The residual liquid from the distillation has generally been sold together with the solids portion of the mash as “distillers' dry grain.” The distillers' dry grain generally is used as feed for livestock.